Interventional pulmonology for asthma and emphysema: bronchial thermoplasty and bronchoscopic lung volume reduction

Emphysema and asthma are responsible for economic and social burden. Altering the natural course of these diseases is a field of intense research. The National Emphysema Treatment Trial showed that lung volume reduction surgery (LVRS) could significantly reduce both morbidity and mortality in properly selected patients. LVRS is seldom performed, however, due to the high morbidity associated with the surgery. Numerous bronchoscopic interventions have been introduced with the goal of providing the clinical benefits of LVRS without the surgical complications. Thus far, these modalities have not produced the results once hoped. However, through active modification of both technique and patient selection, the role of minimally invasive modalities in the treatment of emphysema continues to evolve. Bronchial thermoplasty (BT) is a method of delivering controlled heat to airway mucosa with the goal of reducing airway smooth muscle mass and hence bronchoconstriction. In patients suffering from asthma who cannot achieve control with standard medical care, BT has been shown to be safe and improves symptoms, with long lasting benefit. BT does not seem to affect traditional markers of asthma severity such as forced expiratory volume in 1 second and questions remain regarding proper patient selection for this therapy and its true physiologic effects. This article is a review of bronchoscopic modalities for emphysema and asthma.